The burbot actually spawn on shallow flats adjacent to steep dropoffs for the most part. Like JRS said, the spawn is still a couple weeks away, but now is the time to fish the right on the transition from shallow to deep, as they'll be periodically coming out of the depths to the spawning areas (this is what Western Sportsman has told me).
From my own experience though, during the spawn, they'll all be up on the shallow flats in their ling minage a' trois'. It's quite the thing to see. Last year at Sylvan we were watching the aqua view when a HUGE slithering orgy of burbot swam in. THis happened several times throughout the day. The same day, we were actually perch and white fishing with the aqua vu, and saw sediment being kicked up off-screen. We maneuvered the camera over, and to our surprise, actually watched a female laying her eggs under a log. She would sweep away at the sediment with her tail, creating the burbot equivalent to a redd (like trout do in flowing water). If we'd been able to record it we could have sold it to Alberta Geographic
. It was interesting too, because the Perch and WHitefish were coming in from all over to collect the stray eggs, but weren't interested in maggots.
Hope this helps!
Moults